1. Field of the Invention
The present invention relates to techniques for displaying images.
2. Background Art
Images may be transmitted for display in various forms. For instance, television (TV) is a widely used telecommunication medium for transmitting and displaying images in monochromatic (“black and white”) or color form. Conventionally, images are provided in analog form and are displayed by display devices in the form of two-dimensional images. More recently, images are being provided in digital form for display in two-dimensions on display devices having improved resolution. Even more recently, images capable of being displayed in three-dimensions are being provided.
Conventional displays may use a variety of techniques to achieve three-dimensional image viewing functionality. For example, various types of glasses have been developed that may be worn by users to view three-dimensional images displayed by a conventional display. Examples of such glasses include glasses that utilize color filters or polarized filters. In each case, the lenses of the glasses provide two-dimensional images of differing perspective to the user's left and right eyes. The images are combined in the visual center of the brain of the user to be perceived as a three-dimensional image. In another example, synchronized left eye, right eye LCD (liquid crystal display) shutter glasses may be used with conventional two-dimensional displays to create a three-dimensional viewing illusion. In still another example, LCD display glasses are being used to display three-dimensional images to a user, where the lenses of the LCD display glasses include corresponding displays that provide images of differing perspective to the user's eyes, to be perceived as three-dimensional.
Problems exist with such techniques for viewing three-dimensional images. For instance, persons that use such displays and systems to view three-dimensional images may suffer from headaches, eyestrain, and/or nausea after long exposure. Furthermore, some content, such as two-dimensional text, may be more difficult to read and interpret when displayed three-dimensionally. To address these problems, some manufacturers have created display devices that may be toggled between three-dimensional viewing and two-dimensional viewing. A display device may be switched to a three-dimensional mode for viewing of three-dimensional images, and may be switched to two-dimensional mode for viewing of two-dimensional images and/or to provide a respite from the viewing of three-dimensional images.
A lenticular lens is another example of a device that enables video to be displayed in three-dimensions. A lenticular lens includes an array of sub-lenses. The lenticular lens is placed proximate to an array of pixels so that a user's eyes each see a different set of the pixels to create a sense of depth. A disadvantage of lenticular lenses is that the viewer must be positioned in a well-defined location in order to experience the three-dimensional effect. If the viewer moves his/her eyes away from this “sweet spot,” image flipping and/or exacerbation of the eyestrain, headaches and nausea that may be associated with prolonged three-dimensional image viewing may result. Conventional three-dimensional LCD displays that utilize lenticular lenses typically are capable of displaying only three-dimensional images.